Field of the Invention
The invention relates to a method and apparatus for storing video signal data of at least a partial frame in standard memory components having 2.sup.m possible memory addresses, wherein b pixels are addressed by x address bits and z lines are separately addressed by y addressed bits through picture addresses, on the condition that b&lt;2.sup.x, z&lt;2.sup.y and m, b, z, x and y are positive integers.
The storage of video signal data is becoming increasingly important. The publication Siemens Components 26, 1988, No. 6, pages 240 through 245, for instance, discloses a digital television concept in which the central component is a memory device for storing video signal data of the television picture. Through the use of such a memory device it is possible, for instance, to inscribe the arriving video signal data into the memory device and read them out twice, at double speed. That doubles the vertical and horizontal frequencies, as a result of which the previously familiar large area flickering on the screen can be completely eliminated. It is also possible with the memory device to provide television receivers with noise suppression, cross-color reduction and features such as on-screen insets, 9-image split screens and zoom, among others.
Current memory applications for video signals use scanning rasters with b points per line and z lines, where b and z are generally not powers of 2. Nevertheless, the data are memorized in such a way that separate addressing of the pixels and picture lines by address counters is possible. The following memory provisions are conceivable:
a) the use of special memory components with line and column organization adapted to the scanning raster of the video signal;
b) the use of standard memory components, at the cost of an overly large memory capacity; and
c) reducing the video information to a format tailored to the memory organization of standard memory components.
While the use of special memory components with line and column organization adapted to the scanning raster additionally requires memory components adapted to video signal data storage, thus making such components expensive, the provision listed in item c above is advantageous to the extent that standard memory components can be used. However, the video information must be tailored to the memory organization of the standard memory component, which necessarily results in a reduction in video information. If standard memory components are nevertheless to be used, without accepting a reduction in video information, then previously it was only possible to use standard memory components, with an overly large memory capacity. In order to store a frame having 768 pixels and 320 lines with separate pixel and line addressing, one or more standard memory components had to be used, with a total memory organization of 1024 columns and 512 lines. That results in a considerable unused address region. Such a frame is described in greater detail below in the description of the drawings.